Approximately 4.5 million Americans have an intellectual or developmental disability. Concern is increasing about these individuals' nutrition-related behavior and its implications for their health. This article reports on a systematic search of the current literature listed in the PsycINFO and PubMed databases related to nutritional status of adults with intellectual or developmental disabilities. The authors used key terms for nutrition, secondary conditions, and intellectual and developmental disability and categorized literature pertaining to nutrition-related studies of adults with intellectual or developmental disabilities as follows: dietary intake studies, anthropometric assessments of nutritional risks, biochemical indexes, and clinical evaluations.
Approximately 4.5 million Americans have a developmental disability, many of whom also have an intellectual disability. An additional 3 million have an intellectual disability that is due to causes other than developmental (Administration on Developmental Disabilities, 2005). The U.S. Census Bureau (2006) estimates that approximately 6% of Americans (14.3 million) have limited cognitive functioning, mental illness, or emotional illness that interferes with activities of daily living.
Most individuals with intellectual or developmental disabilities are adults living in the community (Prouty & Lakin, 2006). Furthermore, the U.S. Supreme Court ruled in 1999 that people with disabilities have the right to be served in the most integrated setting appropriate to their needs (Olmstead vs. L.C., 1999). The result has been that adults with intellectual or developmental disabilities are moving out of more restrictive environments, such as institutions and nursing homes, to less restrictive, more independent arrangements with appropriate community-based supports.
Nutrition professionals consider individuals with intellectual or developmental disabilities to be nutritionally vulnerable or at risk for malnutrition, although there is limited scientific evidence on the extent of the problem or individuals' risk (American Dietetic Association [ADA], 2004; Pesce, Wodarski, & Wang, 1989; Springer, 1987; Stewart, Beange, & Mackerras, 1994). It is encouraging that Healthy People 2010 identified nutrition in intellectual or developmental disability as part of the nation's public health agenda, stating, “there are concerns about the nutritional status of persons...with disabilities, including physically, mentally, and developmentally disabled persons in community settings. National data about these population groups are currently unavailable or limited” (Office of Disease Prevention and Health Promotion, 2000, p. 19-5). Based on an intensive review of the literature, in this article, we summarize current knowledge about the nutritional status of adults with intellectual or developmental disabilities.
We do not have enough information yet to determine whether individuals in this population express malnutrition differently or more frequently than the general population. Malnutrition includes overnourishment and/or undernourishment, and people become over- or undernourished in many ways (ADA, 2004). They may consume too little or too much of a nutrient or type of food or may make poor food, diet, or supplement choices. Some individuals become over- or undernourished due to physiologic or metabolic differences (e.g., storing fat differently, gastrointestinal physiology or anatomy), altered nutrient or energy needs, external interference (e.g., medications), or environmental barriers (e.g., finances, lack of nutrition knowledge and support of personal assistance providers; ADA, 2004). Overnourishment may include a pattern of consumption that leads to becoming overweight or developing some cancers or chronic conditions such as cardiovascular disease (CVD) and diabetes. Undernourishment could precipitate nutrient deficiencies leading to anemia, osteoporosis, or wasting in adults. We know very little about these mechanisms and characteristics, their multiple effects on the nutritional status of people with intellectual or developmental disabilities, and how they combine to create poor nutrition. However, we must consider them when developing nutrition and food recommendations and guidelines for persons with intellectual or developmental disabilities.
Nutritionists use several measures to assess an individual's nutritional status and risk: (a) dietary intake analysis, (b) anthropometric testing, (c) biochemical assessments, and (d) clinical examinations. The resulting information, in conjunction with historical records/documents, interviews, and observation of food habits (Gibson, 2005), creates a profile of an individual's status or risk or may be extrapolated to broadly characterize a population's nutritional status or risk. To extrapolate to a population, we must use valid, reliable assessment methods and follow rules of representativeness, including adequate sample size.
Nutritionists may use a single measure or, preferably, a combination of measures to create a comprehensive picture of an individual's or population's nutritional status and risk. Unfortunately, few of these measures have been validated with adults with intellectual or developmental disabilities.
We have organized the following review according to the four primary measurement methods. A fifth section summarizes the literature from food habits and lifestyle studies that used observational, survey, or historical document search methods to gather information about factors that contribute to the nutritional status of adults with intellectual or developmental disabilities.
In this article, we report on a search conducted in 2008 of literature related to the nutritional status and food habits of adults with intellectual or developmental disabilities. The search included publications pertaining to nutrition in the population of adults with intellectual or developmental disabilities, published from 1985 through 2007 (i.e., the past 22 years) and indexed in either the PubMed or PsycINFO databases. PubMed indexes scientific, peer-reviewed health and medical literature. PsycINFO indexes psychological and psychiatric literature. We used both databases to capture publications with a medical–health emphasis or a behavioral–food-habits focus.
Table 1 lists our search terms. We used terms with nutrition content (e.g., dietary intake) and terms to delimit our population of interest (e.g., muscular dystrophy). When searching the databases, we cross-referenced each of the population terms with each of the nutrition terms. We marked each promising entry, read its abstract, and reviewed the full text of each that appeared relevant for inclusion. From the bibliographies of each full-text publication, we also gleaned additional references, obtained their abstracts, and, if applicable, reviewed their full text. In this report, we review those publications on nutritional status, nutritional health, or outcome-oriented nutritional programming in or for adults with intellectual or developmental disabilities.
We reviewed only English-language publications and excluded case studies with little generalizability to the larger population of adults with intellectual or developmental disabilities. We included descriptive studies and reports of empirical research using either a comparison group or pre–post measures of behavior. In all, 71 articles met criteria and were pertinent to characterizing nutrition in adults with intellectual or developmental disabilities using the four primary measurement methods.
In addition, as an educational supplement to the systematic review of the literature of the four primary measurement methods in nutritional research, we reviewed 86 articles to provide insight into other factors that may contribute to or be important in defining the diets, dietary habits, and health consequence for adults with intellectual or developmental disabilities. They did not necessarily meet the strict criteria for inclusion in the systematic literature reviewed in the first four sections. These articles were considered background or preliminary, though having a legitimate place in our expanding understanding of these issues. Some of these articles included are summaries and guiding documents currently in place in the field of nutrition and intellectual or developmental disability.
Some studies we reviewed used multiple assessment methods in their research. For example, CVD risk factors related to nutrition include some dietary (e.g., dietary saturated fat intake), anthropometric (e.g., body fat or body mass index [BMI]), biochemical (e.g., plasma glucose or blood lipids), and clinical measures (e.g., blood pressure).
When a study used multiple assessment techniques, they are listed in Tables 2–5 under the assessment category of the main variable of interest or the one that reflects the primary purpose of the study. For studies that measured a host of nutrition-related factors using multiple methods to indicate risk or presence of a clinical condition, we have listed that article only in Table 5 under Clinical Studies. However, if the variables in a single study were measures taken independently to describe the population, the study is listed under in each of the appropriate tables.
Dietary Intake Studies
When used judiciously, dietary intake (i.e., what people eat) may indicate dietary adequacy and provide a picture of an individual's or group's nutritional status. In general, there are two types of dietary intake measures: retrospective (e.g., 24-hr recall, food frequency, or food history surveys) and prospective (e.g., weighed or estimated food records). Retrospective methods rely on the respondent's memory of what he ate or usually eats during a defined period of time. In prospective methods, for a specified recording period, the respondent records what, when, and how much he ate. The retrospective methods balance reliability of responses with a fairly low respondent burden and avoid the respondent's reacting to the measurements or changing her dietary intake because of the recording process (Gibson, 2005). However, by avoiding the memory variable and recording intake at the time of consumption, under ideal conditions, prospective methods achieve more accurate accounts of the diet content and amount consumed.
Nutritionists have not validated a method for dietary intake assessment for adults with intellectual or developmental disabilities because of significant barriers to collecting valid data. Problems with memory, comprehension, dexterity, literacy, and communication make recalling, recording, and estimating quantities a challenge.
Individuals exhibit a wide range of ability to remember, record, and accurately describe what they eat. Adults with intellectual or developmental disabilities are a nutritionally vulnerable population who could benefit from dietary monitoring, but many researchers posit that these individuals are least likely to provide accurate dietary intake data via traditional prospective or retrospective methods (Braunschweig et al., 2004; Humphries, Traci, & Seekins, 2008; Kumanyika, Tell, Shemanski, Martel, & Chinchilli, 1997; Lindquist, Cummings, & Goran, 2000; Smith, 1993; van Staveren, de Groot, Blauw, & van der Wielen, 1994).
Despite the challenges, dietitians and nutritionists continue to attempt to measure the dietary intake of individuals with intellectual or developmental disabilities because so many factors affecting this population (e.g., dysphagia, gastrointestinal problems, living situations not conducive to adequate and/or healthy diets) suggest a compromised dietary intake.
Using the support of a proxy reporter works well for some more dependent populations (e.g., children, institutionalized, or incarcerated individuals). This method's reliability depends on the constant presence of the proxy during all eating occasions and on the proxy's ability to accurately record foods and amounts.
Most of the dietary intake studies we reviewed used only a proxy reporter (Bertoli et al., 2006; Braunschweig et al., 2004; Bryan, Allan, & Russell, 2000; Cunningham, Gibney, Kelly, Kevany, & Mulcahy, 1990; Humphries et al., 2004, 2007; Lindeman, 1991; Litchford & Wakefield, 1985; McGuire, Daly, & Smyth, 2007; Mercer & Ekvall, 1992; Molteno, Smit, Mills, & Huskisson, 2000; Razagui, Barlow, Izmeth, & Taylor, 1991; Robertson et al., 2000). The use of proxy reporters for adults with intellectual or developmental disabilities limits the collection of dietary intake data from recalls and records to only those individuals with continuous support (i.e., direct observers) for all food-related needs and no access to food independent of that proxy reporter. Proxy reporters record foods that they see an individual consume but cannot monitor the individual's unsupervised food choices. As more adults with intellectual or developmental disabilities gain greater independence, we cannot assume they will have the constant supervision necessary to conduct proxy dietary intake analysis. The use of a proxy in conjunction with interviews and self-reporting is a promising and recommended approach but has not been validated for dietary intake data collection with adults who have intellectual or developmental disabilities (e.g., Draheim, Williams, & McCubbin, 2002a; Mann, Zhou, McDermott & Poston, 2006; Seekins, Traci, Bainbridge, & Humphries, 2005).
Table 2 summarizes 15 dietary intake studies relevant to adults with intellectual or developmental disabilities and published from 1985 through 2007. Two other studies used dietary intake as one of a host of risk factors for CVD and are displayed in Table 5 only. Three studied institutionalized adults (Cunningham et al., 1990; Litchford & Wakefield, 1985; Molteno et al., 2000), 12 studied adults living in community settings (Bertoli et al., 2006; Braunschweig et al., 2004; Draheim et al., 2002a, 2007; Humphries et al., 2007; Humphries, Traci, & Seekins, 2004; Lindeman, 1991; Mann et al., 2006; McGuire et al., 2007; Robertson et al., 2000; Seekins et al., 2005; Stewart et al., 1994), 1 compared a cross-section of samples from the community and from an intermediate care facility (Mercer & Ekvall, 1992), and 1 study assessed dietary intake longitudinally in a sample of adults as they moved from an institution to a community residence (Bryan et al., 2000). Of the community-based studies, 3 studied dietary intake via menu review (Humphries et al., 2004; Lindeman, 1991; Mercer & Ekvall, 1992), 1 used 7-day food records (Bertoli et al., 2006), 7 used a food frequency questionnaire (Braunschweig et al., 2004; Draheim, 2007; Draheim et al., 2002a; Humphries et al., 2007; McGuire et al., 2007; Robertson et al., 2000; Seekins et al., 2005), and 2 used diet history (Mann et al., 2006; Stewart et al., 1994). In addition, 2 studies attempted to correlate dietary intake with chronic disease (CVD risk factors; Braunschweig et al., 2004; Draheim et al, 2002a). Neither research group was satisfied that the dietary intake data collected were accurate or that the methods were valid; the picture the studies paint as a whole is not clear. These two studies are listed in Table 2 among the clinical studies. Table 2 summarizes the dietary intake studies and the populations studied (i.e., institutionalized, community dwelling, or in transition from institution to community), methods used, variables tested, and results.
Researchers have explored other methods for gathering dietary intake information. The National Center for Health Statistics (2002) conducts the National Health and Nutrition Examination Survey (NHANES), a nationwide, ongoing surveillance project that collects health data, including information on Americans' diets. Each year, NHANES researchers conduct in-person and telephone, 24-hr–recall, dietary intake interviews. NHANES facilities and procedures are becoming more physically accessible to individuals with disabilities. The NHANES mobile testing unit is now accessible to an adapted wheelchair, although individuals must transfer into that chair to access the testing site. NHANES does not exclude people with intellectual or developmental disabilities from participating, but the stringent reliability criteria for the NHANES 24-hr recall exclude data from participants who appear “very confused or confused with the 24-hour recall period, or who had a very difficult time remembering and not giving a reasonable effort or changed their mind several times” (National Center for Health Statistics, 2002). Researchers have not analyzed nutritional data for NHANES participants with intellectual or developmental disabilities as a subpopulation.
Humphries et al. (2008) evaluated diet-recall data from repeated implementation of the NHANES protocol with 11 adults having intellectual or developmental disabilities. None of the recalls (N = 25) met the standard reliability criteria (Humphries et al, 2008) for inclusion in the NHANES dataset. Therefore, it is questionable whether this national database is representative of individuals with intellectual or developmental disabilities.
The Behavioral Risk Factor Surveillance System (BRFSS) is another federally funded, ongoing national health survey that provides some dietary intake data (National Center for Chronic Disease Prevention and Health Promotion, 1984). It uses a random-digit-dial telephone- sampling and interview method. BRFSS findings cannot be confidently generalized to adults with intellectual or developmental disabilities because BRFSS does not sample institutionalized individuals; people in households without telephones; individuals with cognitive, speech, and other communication impairments; or people who cannot get to the telephone. There has been no analysis of nutritional data for BRFSS participants with intellectual or developmental disabilities.
Anthropometric Assessment of Nutritional Status and Risk
Anthropometry is defined as measurement of the human body's variations in physical dimension and composition at different age levels and degrees of nutrition (Jelliffe, 1966). In adults, typical anthropometric measures reflecting over- and undernutrition include measurements of body stature, weight, the relationships between body stature and weight (e.g., Quetelet's Index or Body Mass Index [BMI]), and body composition. Table 3 summarizes reviews of reports on anthropometric assessments of nutritional status and risk in adults with intellectual or developmental disabilities.
Anthropometric methods to measure over- or undernutrition based on body size and composition include skinfold calipers, tape measurements of the body, dual x-ray absorptiometry (DEXA) or other body scans, measured or reported (self or proxy) heights and weights, and BMI calculations based on the data. Anthropometric data can provide a picture of over- and undernutrition within the population of adults with intellectual or developmental disabilities, as well as some diagnosis-specific information about that malnutrition. Table 3 summarizes the results of 28 studies using anthropometric data to assess nutritional status or risk in adults with intellectual or developmental disabilities.
The inconsistency of methods used to gather anthropometric data for nutritional assessment of adults with intellectual or developmental disabilities makes it difficult or imprudent to compare results. For example, some researchers use skinfold calipers to identify individuals who are overweight or obese (Bertoli et al., 2006; Rimmer, Braddock, & Fujiura, 1993; Rubin, Rimmer, Chicoine, Braddock, & McGuire, 1998), whereas other studies report on BMI calculated from heights and weights taken in person or from medical records (Braunschweig et al., 2004; Draheim, McCubbin, & Williams, 2002; Draheim et al., 2002a; National Center for Health Statistics, 2002). Some researchers use proxy-reported heights and weights to assess weight conditions (Janicki et al., 2002; McGuire et al., 2007; Rubin et al., 1998; Yamaki, 2005), and others use derived BMIs to categorize weight risks (Rubin et al., 1998; Yamaki, 2005).
We must consider the difficulty of measurement when attempting to explain the complicated picture of weight problems in individuals with intellectual or developmental disabilities. Measuring overweight and obesity in individuals living in more independent settings may be more challenging than for those in institutional settings. For example, Bryan, Allan, and Russell (2000) found that 15% of 118 participants could not be weighed due to unavailability of suitable, accessible scales in the community.
Different researchers also have used differing standards to determine what underweight, normal weight, overweight, and obesity are in individuals with intellectual or developmental disabilities, which compounds the inconsistency. Because the studies reviewed reported varying methods and standards, we could not do a meta-analysis of weight-related nutritional risk research. In the results reported here, we used the authors' standards for weight status, and we did not report these data in the aggregate.
Overall, anthropometric assessments of adults with intellectual or developmental disabilities have shown a bimodal distribution of body weights outside the normal range. Both over- and undernutrition, resulting in poor weight status, are concerns in this population.
The national health objectives for 2010 have ranked obesity among the top 10 leading health indicators (Office of Disease Prevention and Health Promotion, 2000). Obesity and overweight in the general population are associated with higher mortality and morbidity rates, and obesity in the general population contributes to arthritis, some cancers, decreased lung capacity, depression, diabetes, gallstones, gout, heart disease, hypertension, insulin resistance, respiratory disease, sleep disorders, stress, and stroke (Eckel, 1997; National Task Force on the Prevention and Treatment of Obesity, 2000; Obesity Education Initiative, 1998; Pi-Sunyer, 1999). In one study, adults with intellectual or developmental disabilities who were overweight or obese reported more limitation in daily life than those with normal weight (Seekins et al., 2005). In addition to its medical ramifications, obesity is a barrier to integrating adults with intellectual or developmental disabilities into the community (Rimmer et al., 1993). Studies have shown a strong link between obesity and discrimination against this population (American Dietetic Association [ADA], 2004). The ADA has asserted that underweight and maintaining adequate weight also can be problems that put adults with intellectual or developmental disabilities at nutritional risk. However, less is known about the risks of underweight and any associated additional disability.
The bulk of the literature has indicated that in most Western countries, and particularly in the United States, adults with intellectual or developmental disabilities are heavier than the general population and that overweight and obesity are major nutritional problems for this population (Beange, McElduff, & Baker, 1995; Bell & Bhate, 1992; Braunschweig et al., 2004; Cole, 1986; Draheim, McCubbin, & Williams, 2002; Draheim et al., 2002a; Rimmer, Braddock, & Fujiura, 1994; Rubin et al., 1998; Stewart et al., 1994; Yamaki, 2005). For a review of obesity and intellectual disability, see Rimmer and Yamaki (2006).
Nutrition surveys of anthropometric data have shown higher levels of overweight in adults with all types of disabilities (Office of Disease Prevention and Health Promotion, 2000), and Yamaki (2005) reported that, in the years 1985–2000, obesity increased significantly in noninstitutionalized adults with intellectual or developmental disabilities.
Individuals diagnosed with mild or moderate intellectual disability, or who are considered “more able,” experience more overweight and obesity than do adults with profound intellectual disability (Molteno et al., 2000; Robertson et al., 2000). However, this may be mediated by the degree of independence in living setting (Cunningham et al., 1990). Adults with intellectual or developmental disabilities who have relatively higher IQs and who score higher on nutrition knowledge tests experience higher rates of obesity (Golden & Hatcher, 1997).
Women with intellectual or developmental disabilities experience disproportionately higher rates of overweight and obesity than do men with intellectual or developmental disabilities (Beange et al., 1995; Bell & Bhate, 1992; Cunningham et al., 1990; Emerson, 2005; Frey & Rimmer, 1995; Melville, Cooper, McGrother, Thorp, & Collacott, 2005; Molteno et al., 2000; Rimmer et al., 1993; Rubin et al., 1998; Stewart et al., 1994; Yamaki, 2005). Prevalence rates of overweight and obesity in U.S. adults with intellectual or developmental disabilities parallel those of the U.S. general adult population in being higher than those of other countries (Frey & Rimmer, 1995; Harris, Rosenberg, Jangda, O'Brien, & Gallagher, 2003).
Researchers have recorded a high prevalence of obesity in adults with intellectual or developmental disabilities in both institutional and community settings (Bertoli et al., 2006; Burkart, Fox, & Rotatori, 1985; Cunningham et al., 1990; Emerson, 2005; Hoffman, Aultman, & Pipes, 1992; Marshall, McConkey, & Moore, 2003; Merriman, Kirk, & Stubbs, 2005; Prasher, 1995; Rimmer et al., 1993; Robertson et al., 2000; Simila & Niskanen, 1991; Stewart et al., 1994; Traci, Seekins, Szalda-Petree, & Ravesloot, 2002). However, adults with intellectual or developmental disabilities who live in the community have higher prevalence rates of overweight and obesity than do individuals in institutions (Bryan et al., 2000; Frey & Rimmer, 1995; Prasher, 1995; Rimmer et al., 1993). Longitudinal studies of individuals moving from institutions to supported arrangements have shown significant weight changes and increased limitations as a result of weight (Bryan et al., 2000; Gabre, Martinsson, & Gahnberg, 2002; Seekins et al., 2005; Springer, 1987).
Some findings that have shown residence to be a significant predictor of overweight suggest that age and other factors may complicate the picture (Rubin et al., 1998). As with the general population, overweight and obesity in adults with intellectual or developmental disabilities appear to increase through midlife (Burkart et al., 1985; Hand, 1994; Yamaki, 2005). Hand (1994), for example, did not find significant differences in overweight and obesity in elderly adults with moderate to profound disabilities who lived in community versus institutional settings. Levels of disability and age may be additional critical factors in who becomes obese rather than an individual's residential setting. This speculation could evolve to include other factors (e.g., gender, race–ethnicity, specific impairment), with research needed to determine relative risk ratios controlling for other factors.
Some developmental disabilities, including Prader-Willi syndrome (Brambilla et al., 1997) and Down syndrome (Melville et al., 2005; Molteno et al., 2000; Prasher, 1995; Rimmer & Wang, 2005) are associated with obesity unless intensive support is in place to balance energy intake and output. Atypical body composition (e.g., disproportionately high fat and unusual fat distribution) also may appear in the type of obesity associated with some developmental disabilities, such as Prader-Willi syndrome (Brambilla et al., 1997).
In more highly developed countries, underweight is less prevalent than overweight in adults with intellectual or developmental disabilities, but its prevalence is disproportionately high compared with that for adults without intellectual or developmental disabilities, both for individuals in institutions (Beange et al.,1995; Kennedy, McCombie, Dawes, McConnell, & Dunnigan, 1997; Macdonald, McConnell, Stephen, & Dunnigan, 1989; Molteno et al., 2000) and for those living in the community (Bryan et al., 2000; Emerson, 2005; Hove, 2004; Robertson et al., 2000; Simila & Niskanen, 1991; Stewart et al., 1994). Individuals with more profound disabilities experience higher rates of undernutrition (Beange et al., 1995; Simila & Niskanen, 1991; Stewart et al., 1994) due to more feeding problems, chewing and swallowing problems, and general dietary risk. The bimodal distribution of body weight and BMI for adults with intellectual or developmental disabilities illustrates this unusually high prevalence of both underweight and overweight.
Biochemical Assessment of Nutritional Status and Risk
There are many biochemical tests of body tissues to assess nutritional status and health risk. However, published reports on biochemical testing of adults with intellectual or developmental disabilities are few and limited to dehydration and serum concentration of urea and electrolytes (Macdonald et al., 1989); CVD risk factors, such as blood lipids (Bertoli et al., 2006; Braunschweig et al., 2004; Draheim, McCubbin, & Williams, 2002; Draheim et al., 2002a; Rimmer et al., 1994), C-reactive protein (Butler, Bittel, Kibiryeva, & Garg, 2006), and blood glucose and insulin (Bertoli et al., 2006; Braunschweig et al., 2004; Draheim, McCubbin, & Williams, 2002; Draheim et al., 2002a); bone health, including vitamin D status and markers of bone remodeling (Center, Beange, & McElduff, 1998; Wong, Lau, Lim, & Fung, 2006; Zubillaga et al., 2006); iron- and copper-related anemias (Molteno et al., 2000; Razagui et al., 1991); vitamins B12 (Morad, Gringols, Kandel, & Merrick, 2005) and B6 (Ellman et al., 1986); other nutrient deficiencies (Cole et al., 1985); and appetite and fat-deposition hormones, including leptin (Cento et al., 1999; Hoybye, Barkeling, Espelund, Petersson, & Thoren, 2003; Komori et al., 2004; Proto et al., 2007; Weigle et al., 1997), ghrelin (DelParigi et al., 2002; Goldstone et al., 2004, 2005), and neuropeptide Y and oxytocin (Hoybye et al., 2003). Table 4 summarizes our review of reports on biochemical assessments of nutritional status and risk in adults with intellectual or developmental disabilities.
Clinical Assessments as Indicators of Poor Nutritional Status and Additional Risk
A clinical nutritional assessment includes a medical history to establish patient-reported physical symptoms of malnutrition or of a nutrition-related disease or condition. A qualified practitioner may also conduct a physical examination for signs of malnutrition, nutrition-related conditions, or disease (Gibson, 2005). Because the body's inclination for homeostasis compensates for minor and early stages of nutrient imbalances, clinical measures are most useful when an individual has advanced stages of nutrient excess or depletion. Table 5 summarizes our review of reports on clinical assessments of nutritional status and risk in adults with intellectual or developmental disabilities.
Additional physical or psychological problems frequently complicate primary disabilities. The accepted framework of health promotion for people with disabilities refers to these health problems as secondary conditions (Brandt & Pope, 1997; Marge, 1988; Office of Disease Prevention and Health Promotion, 2000; Pope & Tarlov, 1991). Marge (1988) defined secondary conditions as conditions that individuals with a primary (or first) disability may subsequently experience. Aside from general overweight, individuals with more severe intellectual disability have a higher incidence of disabling secondary clinical conditions (Hayden, 1998).
Until recently, researchers commonly saw such conditions as symptomatic of the primary disability; however, they now presume that these preventable and/or manageable conditions are secondary conditions distinct from the primary disability's symptoms. Nutrition plays an important role in preventing and managing health-related secondary conditions throughout the lifespan of people with intellectual or developmental disabilities. In addition, some common secondary conditions, such as depression, can adversely affect food intake and food habits, leading to more health problems for adults with intellectual or developmental disabilities (O'Brien & Whitehouse, 1990).
Clinical assessments can test for and detect most nutrition-related secondary conditions. Such testing is crucial and tends to be more convincing of an individual's nutrient excess or inadequacy than other nutritional assessment tools (e.g., dietary intake assessment, anthropometry, biochemical tests). However, waiting for secondary conditions or physical limitations to manifest themselves can delay proactive nutritional treatment that might prevent or ameliorate the conditions (Havercamp, Scandlin, & Roth, 2004).
Some studies have reported that adults with intellectual or developmental disabilities do not access medical providers as often as adults without intellectual or developmental disabilities; nor do they receive equal rates of health promotion or preventive services (Krahn, Hammond, & Turner, 2006). When adults with intellectual or developmental disabilities do visit health care providers, they may experience difficulty in communicating their symptoms and being understood. This puts them at risk for misdiagnosis, inappropriate treatment, or failure to be treated (Janicki et al., 2002).
A broad approach to identifying secondary conditions in adults living in the community with learning disability was published by Stewart and colleagues in 1994. Among important secondary conditions tested were blood pressure, blood cholesterol, gastrointestinal problems, dysphagia, food allergies or intolerances, weight problems, and poor dietary intake (Stewart et al., 1994).
A combined self-report–proxy-report survey of clinical symptoms by Seekins and colleagues (2005; Traci et al., 2002) characterized the most limiting health and medically identified secondary conditions affecting a sample of adults with intellectual or developmental disabilities who lived in the community. The researchers identified nutrition as a possible risk or protective factor for a variety of secondary conditions: weight problems, physical fitness and conditioning problems, dental and oral problems–hygiene, depression, fatigue, bladder dysfunction, bowel dysfunction, eating problems and gastrointestinal dysfunction, side effects from medications (drug–nutrient interactions), allergies and allergic reactions, diabetes, cancer, urinary tract infections, osteoporosis, cardiovascular–circulatory problems, nutritional deficits, postural hypotension, anemia, alcohol–drug abuse, and environmental equipment failures that might limit food planning, purchase, preparation, and so forth (Seekins et al., 2005). Clinical nutrition investigations have examined several of these reported secondary conditions, including CVD, bone health, gastrointestinal dysfunction, and eating problems.
Researchers report that adults with intellectual or developmental disabilities are at a high risk for CVD due to elevated blood lipids, high rates of hypertension, and obesity (Beange et al., 1995; Draheim et al., 2002, 2002a; Merriman et al., 2005; Rimmer, Braddock, & Marks, 1995; Rimmer et al., 1993, 1994; Stewart, et al., 1994; ; Traci et al., 2002). The subpopulation of adults with mild to moderate intellectual or developmental disabilities who live in community settings are of particular concern. Draheim (2006) reviewed CVD prevalence and risk factors in this population.
Researchers have found that, compared with adults without intellectual or developmental disabilities, adults and young adults with intellectual or developmental disabilities are at increased risk for poor bone health, including having bones with low mineral content and/or density (Baptista, Varela, & Sardinha, 2005; Bertoli et al., 2006; Center et al., 1998; Sakadamis, Angelopoulou, Matziari, Papameletiou, & Souftas, 2002; Sepulveda et al., 1995), reduced bone strength (Baptista at al., 2005), osteoporosis (Center et al., 1998; Traci et al., 2002), and fractures (Center et al., 1998; Tannenbaum, Lipworth, & Baker, 1989; Tohill, 1997).
According to the Health Guidelines for Adults With an Intellectual Disability (Santos-Teachout et al., 2002), contributing factors to poor bone health in adults with intellectual or developmental disabilities include use of anticonvulsants, low sunlight exposure, poor dietary intake of calcium, and being a postmenopausal woman or hypogonadal man. Nutrition organizations have not developed calcium intake guidelines for osteoporosis prevention in individuals with intellectual or developmental disabilities (Rimmer & Braddock, 2002), although such guidelines are needed (Brambilla et al., 1997; Goldstone et al., 2002; Schoeller, Levitsky, Bandini, Dietz & Walczak, 1988).
Researchers have reported on gastrointestinal problems, including diarrhea and constipation, in adults with intellectual or developmental disabilities living in the community (Traci et al., 2002) and in institutions (Bohmer et al., 2001; Fischer et al., 1985). Adults with intellectual or developmental disabilities frequently use medications with normative side effects of constipation, hemorrhoids, and other gastrointestinal problems (Bohmer, Taminiau, Klinkenberg-Knol, & Meuwissen, 2001; Bohmer et al., 1997). Some adults with intellectual or developmental disabilities have other behaviors or lifestyle habits that may contribute to constipation and/or diarrhea, such as the use of some medications, habitual use of laxatives or enemas, poor diet and food refusal, physical inactivity, habitually ignoring urges to defecate, low intake of fiber from fruits and vegetables, and other dietary factors (Bohmer et al., 2001; Davis & Sherer, 1994; Seekins et al., 2005; Taylor, 1990).
Researchers have identified many eating problems that have nutritional consequences for individuals in this population, including chewing problems, gastroesophageal reflux, and oral preparatory and oral- and pharyngeal-stage dysphagias (Bohmer et al., 1997; Hennequin, Allison, Faulks, Orliaguet, & Feine, 2005; Sheppard, Liou, Hochman, Laroia, & Langlois, 1988; Traci et al., 2002; Wodarski, 1985). Due to varying operational definitions of dysphagia among studies, researchers have reported that a wide range (10%–97%) of adults with profound intellectual or developmental disabilities exhibit eating problems (Chadwick, Jolliffe, & Goldbart, 2003; Sheppard et al., 1988; Traci et al., 2002). Dysphagia in individuals with intellectual or developmental disabilities may cause dehydration, aspiration and asphyxiation, low body weight, upper respiratory infection, anorexia, vomiting, and pneumonia (Helfrich-Miller, Rector, & Straka, 1986; Kennedy et al., 1997; Sheppard et al., 1988; Wood, 1994).
More children than adults tend to have neuromuscular dysfunction and distracting behavior that create feeding problems affecting nutrient intake (Pesce et al., 1989; Springer, 1987). For example, Sanders and colleagues (1990) found that children with cerebral palsy who have difficulty swallowing, chewing, or sucking tend to be underweight and undernourished. By adulthood, specialized diets, therapies, and other supports often have addressed, even if not entirely resolved, these problems. Eating skills appear to develop later, and mechanical feeding problems are less problematic across adult samples.
Other Factors Contributing to Nutritional Status in Adults With Intellectual or Developmental Disabilities
There are few studies on the role of genetics in secondary conditions experienced by adults with intellectual or developmental disabilities, including CVD, diabetes, and overweight. In preliminary findings, Traci and colleagues (2001) showed that adults with intellectual or developmental disabilities who had a known family history of weight problems also had statistically higher BMIs than respondents without such a history (Traci et al., 2001). Other researchers have tested adults with Down syndrome to determine whether they have a protective genetic factor against cardiovascular disease (Braunschweig et al., 2004; Draheim et al., 2002).
Food habits and lifestyle
Although each individual has unique behaviors, motivations, and opportunities for improved nutrition, a group of people may share some food and lifestyle habits. Nutrition professionals can determine a group's common pressures, barriers, strengths, and opportunities for nutrition education and intervention. Researchers use social science approaches to study food habits and lifestyle practices of adults with intellectual or developmental disabilities that affect their dietary intake, their use of nutrients, and other factors that may lead to malnutrition or nutrition-related secondary conditions.
Nutritionists generally believe that physical activity, weight management, and nutritional status are related (ADA, 2002). Exercise has positive effects on nutrition-related secondary health conditions in adults with intellectual or developmental disabilities (Draheim, Williams, & McCubbin, 2002b).
Researchers have found that adults with intellectual or developmental disabilities have low levels of exercise and physical activity (Beange et al., 1995; Draheim et al., 2002b; McGuire et al., 2007; Pitetti & Campbell, 1991; Rimmer et al., 1993, 1995; Robertson et al., 2000; Seekins et al., 2005; Wells, Turner, Martin, & Roy, 1997), although in some cases not necessarily lower than adults without disabilities (Emerson, 2005). Others have found that adults with intellectual or developmental disabilities are more likely to be sedentary (Havercamp et al., 2004) and to sleep more than adults without disabilities (Beange et al., 1995).
Medications taken by adults with intellectual or developmental disabilities to manage disability-related problems can negatively affect their nutritional status (ADA, 2004; Aman, 1987; Docktor, 1998). In certain circumstances (e.g., long-term use, in combination with other drugs, or taken with a marginally adequate diet), many of these medications can affect an individual's nutritional status (Bohmer et al., 2001; Cimino, Epel, & Cooperman, 1985; Docktor, 1998; Reiss & Aman, 1997; Tohill, 1997).
Side effects of medications, such as changes in the sense of taste, decreases or increases in appetite, dry mouth, or nausea, may affect food intake. Medications may alter stomach acidity; absorption (mucosal disruption); digestion, assimilation, and metabolism of nutrients; hormonal functioning; or water retention and dehydration (ADA, 2003). Adults with intellectual or developmental disabilities who take psychotropic drugs more often experience weight gain (Hellings, Zarcone, Crandall, Wallace, & Schroeder, 2001) and/or higher BMI than do individuals not taking such drugs (Merriman et al., 2005), but appetites may increase or decrease (Rimmer & Braddock, 2002; Sutton, Factor, Hawjubs, Heller, & Seltzer, 1993). Scientists do not fully understand the mechanisms of weight gain on psychotropic medications (Blackburn, 2000), but it appears that available treatments, including calorie restriction, do not manage weight effectively (Cohen, Clazewski, Khan, & Khan, 2001).
Food habits and unusual food practices
Nutrition and food habits may be partly to blame for high rates of overweight and obesity and other secondary conditions in adults with intellectual or developmental disabilities (Bechtel & Schreck, 2003; Bryan et al., 2000; Draheim et al., 2002a; Rubin et al., 1998; Seekins et al., 2005; ).
Gravestock's (2000) literature review on eating disorders and adults with intellectual disabilities highlighted pica, rumination–regurgitation and psychogenic vomiting, food fads–refusal and psychogenic loss of appetite, binge eating disorders, and anorexia nervosa as behaviors and conditions that could have a negative impact on the diet and nutrition of adults with intellectual or developmental disabilities.
Some individuals with Prader-Willi syndrome eat inappropriately, may eat excessive amounts, may steal and hoard food (Holland, Treasure, Coskeran & Dallow, 1995), practice pica (Dykens, 2000; Hoffman et al. 1992; Pipes, 1992), and/or eat contaminated foods (Dykens, 2000). Often these individuals' access to food is restricted (Holland et al., 1995; Hoffman et al., 1992), causing difficult decisions regarding appropriate choice and autonomy.
U.S. policies, such as the Olmstead decision, encourage deinstitutionalization, integration into the community, and increased independence for individuals with intellectual or developmental disabilities. Both transition to the community and type of community residential setting appear to influence the individual's formation of food and lifestyle habits affecting nutritional status. Because most adults with intellectual or developmental disabilities now live in community settings (Prouty & Lakin, 2006), this warrants additional research. Institutions have nutrition professionals to plan and implement diets, and staff provides functional support for eating. Dietary intake among institutionalized individuals is within the normal range according to most accepted nutritional recommendations (Cunningham et al., 1990; Ellman & Salfi, 1986; Litchford & Wakefield, 1985; Molteno et al., 2000), but that is not necessarily the case in community residences (Bryan et al., 2000; Humphries et al., 2004; Robertson et al., 2000).
Still, measuring food intake in community-dwelling adults with intellectual or developmental disabilities presents such methodological difficulties that we cannot confidently draw conclusions regarding type of residence as a key variable in determining the adequacy or healthfulness of individuals' diets.
It appears that weight management, including both avoiding overweight and underweight, is more difficult in community settings (Bryan et al., 2000; Emerson, 2005; Frey & Rimmer, 1995; Gabre et al., 2002; Hove, 2004; Prasher, 1995; Rimmer et al., 1993; Robertson et al., 2000; Simila & Niskanen, 1991; Springer, 1987; Stewart et al., 1994; Yamaki, 2005). Adults living in community settings have a higher rate of CVD than individuals living in institutions (Pitteti & Campbell, 1991); poor diet is postulated to be a critical factor in this.
Whereas residential type influences nutritional status, the converse appears to be true as well; nutritional status and food habits may influence residential placements for adults with intellectual or developmental disabilities. Poor nutrition is a risk for individuals with disabilities moving from living settings that offer greater support into more independent settings (Bryan et al., 2000; Robertson et al., 2000; Springer, 1987). Nutrition-related behaviors, such as the individual's ability and willingness to shop, cook, and eat healthy foods; events such as weight gain (Rimmer et al., 1993) or weight loss (Gabre et al., 2002); and concomitant secondary effects and reported limitations (Seekins et al., 2005) can increase the individual's need for support and may lead to moving into a more restrictive setting.
It is difficult to interpret the data indicating that adults with intellectual or developmental disabilities who live in the community have greater levels of overweight and obesity compared with those living in institutions. As adults with intellectual or developmental disabilities move from institutions into less restrictive settings, the individuals still residing in institutions may be those more likely to be underweight (i.e., medically fragile, with more profound disabilities). Moreover, residential types and definitions vary considerably, and we do not know which of the many factors within each residential type are the most important risk and protective factors for nutrition.
Poor people without disabilities tend to have poor nutrition because they lack sufficient resources for food purchase and planning (Economic Research Service, 2006). The prevalence of low income is high among adults with intellectual or developmental disabilities (Fujiura & Yamaki, 1997; Yamaki & Fujiura, 2002) and may contribute, for the same reasons, to their poor diets and high body weights.
Discussion and Summary
Each of the four nutritional assessment methods reveals specific nutrition concerns for adults with intellectual or developmental disabilities as well as areas for improving the quality of assessment. Some of the nutrition concerns are diagnosis specific and others indict environmental and lifestyle factors.
Dietary intake studies show that there are adequate nutrition data available for adults in institutions and for adults with 24-hr proxy reporters. These data indicate that diets planned and served by qualified food service personnel are generally adequate, given that currently institutionalized adults with intellectual or developmental disabilities often have fragile health. The dietary intake data for adults living in the community are less clear. First, the literature indicates that current dietary intake methods are not adequate to gather valid food intake data in the population of adults with intellectual or developmental disabilities living independently or semi-independently. Proxy reporters are not available for every eating occasion, and self-report using traditional methods of recording or recall has poor reliability. Despite these data collection limitations, the trends indicate that adults with intellectual or developmental disabilities who live in the community subsist on nutritionally poor diets planned and prepared by poorly trained support staff, are lacking guidance in making food selections, and have diets that may be inadequate in some essential nutrients and recommended food groups (e.g., fruits and vegetables and dairy) and excessive in other food groups (e.g., fats, sweets, and junk food).
Findings from anthropometric methods, which have been used to assess the body composition of adults with intellectual or developmental disabilities, create a picture of a population that has a high proportion of overweight and underweight people outside the normal weight range. The research shows effects due to gender, age, residence, and primary disability diagnosis. We lack standardized anthropometric methods and accepted guidelines for categorizing weight and adiposity based on health risk in this population.
Nutritional biochemistry is used to a much larger extent with individuals without disabilities than with adults who have intellectual or developmental disabilities. Lipid biochemistry testing had the most consistent results and showed significant CVD risk factors present in adults with intellectual or developmental disabilities. Researchers have also begun preliminary work with appetite and metabolic hormones in adults with intellectual or developmental disabilities, particularly with those individuals whose primary diagnoses display an appetite–satiety or genetic metabolic element. Research has not been done on establishing the prevalence of deficiency or determining optimal levels of protein, vitamins, macrominerals, and trace elements in adults with intellectual or developmental disabilities.
Clinical assessments of adults with intellectual or developmental disabilities have shown significant problems in the areas of CVD, bone health, gastrointestinal dysfunction, and eating difficulties. The prevalence of these clinical conditions has not been determined precisely, although we presume they are higher due to poor diagnosis and underreporting. Health care utilization literature has indicated that adults with intellectual or developmental disabilities underutilize or do not have access to many preventive screenings (see Sutherland, Couch, & Iacono, 2002).
In summary, this review of the current literature has shown the following:
1. Significant nutrition-related risks exist for adults with intellectual or developmental disabilities, including poor diet, elevated rates of over- and underweight, significant CVD risk factors, and multiple, limiting secondary conditions.
2. Nutrition support professionals, including physicians, need increased awareness and education about nutrition problems and risk factors in this population and available guidelines for screening, testing, and treating them.
3. Although many dietary recommendations for the general public appear to apply to healthy adults with intellectual or developmental disabilities, there is compelling evidence of specific, unique differences that must be examined further and new recommendations established in this population.
4. There is a paucity of scientific research in the field of nutrition and intellectual or developmental disability. Inclusion, as a philosophy in disability rights, can apply to nutrition research as a way to increase our knowledge base of the nutrition-related needs of adults with intellectual or developmental disabilities.
5. There is a need for nutrition standards and clinical and assessment guidelines specific to and appropriate for adults with intellectual or developmental disabilities. Commonly accepted and widely distributed guidelines do not currently exist.
6. Nutrition education for adults living independently is not coordinated, not based on evidence, and not researched for efficacy. These problems are understandable in light of the upstream issues in nutritional assessment seen in this review of the literature. These conclusions from the literature are expanded on and formulated as recommendations in the following section.
Our recommendations from this review of the scientific literature on the nutrition of adults with intellectual or developmental disabilities include roles of support professionals, unique recommendations for nutrient intakes, recommendations for research, creating and using guiding documents and nutrition standards, and nutrition education and supports.
Roles for Support Professionals
It is appropriate for each individual with an intellectual or developmental disability to have an interdisciplinary support team, according to his or her risks and needs. A team might include the individual, his primary physician, dietitian or other nutrition professional, speech pathologist, occupational therapist, physical therapist, vocational rehabilitation counselor, case manager, personal assistant, and family members.
Health care providers, dietitians, and other nutrition professionals need opportunities, incentives, and supports to learn about intellectual or developmental disabilities and how best to provide adequate nutrition services to this population. Primary care physicians should become aware that individuals with intellectual or developmental disabilities have unique nutritional risk factors and need routine assessment of weight, dietary adequacy, physical activity, eating skills, bone density, medication side effects, gastrointestinal problems, as well as screening for other common chronic diseases (e.g., CVD, diabetes, cancer). An individual may need a referral to a nutrition professional and a prescription for a special diet that considers his or her health, unique lifestyle, and personal goals.
Clinical symptoms of deficient or excess nutrients generally appear after the signs are detectable by other nutritional assessment methods, and symptoms can be addressed by nutrition education and dietary interventions alone. Still, comprehensive and regular clinical examinations for nutrition-related secondary conditions should be a part of the routine health care for all adults with intellectual or developmental disabilities. Nutrition organizations should develop clinical assessment guidelines that health care practitioners can use with this population. Adults with intellectual or developmental disabilities should have access to these guidelines so they can help educate their own care providers about their unique health care needs.
Dietitians need to become an educated part of interdisciplinary teams that serve individuals with intellectual or developmental disabilities. There is currently no certification, license, or recognized specialty in dietetics for persons with intellectual or developmental disabilities. There is a Dietary Practice Group on Behavioral Health Nutrition within the ADA but no comprehensive training program for dietitians or members is available. Insurance and Medicaid reimbursements for nutritional services are very limited, and both consumer groups and dietitians should advocate for expanded coverage. Dietetics and nutrition professionals can effectively support caregivers and teach them strategies to recognize and address behaviors associated with cardiovascular health, eating problems, medication interactions and side effects, and gastrointestinal health.
Recommendations for Unique Nutrient Intakes
The Recommended Dietary Allowances (RDAs) are defined as “the levels of intake of essential nutrients that, on the basis of scientific knowledge, are judged by the Food and Nutrition Board to be adequate to meet the known nutrient needs of practically all healthy persons” (National Research Council, 1989, p. 10). The debate continues as to whether the RDAs are applicable to persons with intellectual or developmental disabilities (Cunningham et al., 1990; Ponder & Bergman, 1980). With a few empirically based exceptions (e.g., energy, calcium, vitamin D) and little scientific evidence to the contrary, we assume that nutrient requirements are the same for physically healthy people with or without intellectual or developmental disabilities.
The most pressing concern is an individual's energy requirements. Energy recommendations must account for diagnosis-specific factors, such as cerebral palsy with athetotic movement (Johnson, Goran, Ferrara, & Poehlman, 1996), or unique body composition and lower energy expenditure, such as in Prader-Willi syndrome (Goldstone et al., 2002; Schoeller et al., 1988). Recommendations must also consider the typically sedentary lifestyles of adults with intellectual or developmental disabilities who live in the community.
Research on osteoporosis and calcium metabolism suggests increasing the RDA for calcium and vitamin D in groups of people whose lifestyle is extremely sedentary and who have minimal sun exposure, or for individuals with diagnosis-specific or physical risk factors, such as paralysis or altered body composition (Brambilla et al., 1997; Goldstone et al., 2002; Schoeller et al., 1988; Wong et al., 2006; Zubillaga et al., 2006). However, research has not established recommendations for precise levels of bone-related nutrients.
It is appropriate to make recommendations for improvements in research methodology and design and for specific areas of inquiry. Nutrition research for adults with intellectual or developmental disabilities is not extensive, so researchers must define the best standards and techniques to use with this group of people and seek to achieve consensus on these standards. National, ongoing surveys also need definitions and common procedures to screen participants for disability.
Researchers must develop or modify dietary intake methods and test them for reliability and validity with this population. Nutrition screening is an inexpensive, quick, and often effective way to provide nutritional health care to most individuals. Researchers must develop a nutrition screening instrument based on empirical evidence and validated for adults with intellectual or developmental disabilities. Then, dietary intake studies and screening efforts should characterize the diets of adults with intellectual or developmental disabilities to inform the development of appropriate, acceptable standards and dietary interventions.
Studies of particular nutrients have overlooked participants with intellectual or developmental disabilities, possibly due to the difficulties of recruitment, individuals' classification as a vulnerable research population, or because few nutritional biochemists are trained to work with the unique communication styles and support needs of adults with intellectual or developmental disabilities. Disability advocacy groups might insist that adults with intellectual or developmental disabilities join the pool of research participants to establish, at minimum, the prevalence of nutrient deficiency and recommended levels of intake in this population.
Weight management is of special concern among the rapidly growing numbers of obese adults with intellectual or developmental disabilities. Recent literature indicates that without effective interventions, the problem of overweight and its associated health conditions will become devastating. Effective and acceptable health promotion interventions to manage weight and develop healthy lifestyles that maintain normal weight should be a priority.
After an extensive review of the literature on the health issues of adults with developmental disabilities, Sutherland, Couch, and Iacono (2002) asserted that future studies should address “multi-dimensional perspectives that include examining health and medical conditions, along with health determinants, such as behavioral and environmental factors” (p. 440).
Researchers should continue to conduct nutritional assessment of individuals with developmental disabilities and to develop effective research tools to use with this population. Participants with disabilities need to be part of the testing pool in nutritional research labs and programs and should not be excluded by design, by lack of access, by administrative or technical challenges, or by editing of their data.
Researchers and behavioral sciences experts must collaborate to develop and implement research tools that use self-report methods to gather information from adults with intellectual or developmental disabilities.
Guiding Documents and Standards
Similar to scientific research on nutrition and intellectual or developmental disabilities, practice standards, guidelines, and training opportunities for nutritional practice are limited. Those that exist primarily address the needs of children with developmental disabilities (ADA, 2002; Baer, Blyler, Cloud, & McCamman, 1991; Cloud, 1997; Hine, Cloud, Carrithers, Hickey, & Hinton, 1989; Lucas, 1990) or ways to improve food delivery in institutions (Hogan & Evers, 1997; Litchford & Wakefield, 1985). Researchers should develop nutrition standards to address the known needs and common lifestyle factors of adults with intellectual or developmental disabilities, including a standard for medical nutrition therapy. Such standards would address the issue of the individual's personal choice as well as his or her long-term health goals.
Several publications might guide the development of nutrition standards and guidelines for nutrition for adults with intellectual or developmental disabilities. These include the following:
1. Healthy People 2010, Chapter 6, “Secondary Conditions” (Office of Disease Prevention and Health Promotion, 2000);
2. The Surgeon General's Call to Action for Improving the Health of Persons With Mental Retardation (U.S. Public Health Service [USPHS], 2005) and his report, Closing the Gap: A National Blueprint for Improving the Health of Individuals With Mental Retardation (USPHS, 2002).
3. The ADA's position statement on Providing Nutrition Services for Infants, Children, and Adults with Developmental Disabilities and Special Health Care Needs includes recommendations to the association's membership for providing nutrition services and medical nutrition therapy for persons with developmental disabilities (ADA, 2004).
4. The Dietary Guidelines for Americans (USDA & U.S. Department of Health and Human Services, 2005);
5. MyPyramid, formerly known as the Food Guide Pyramid, is a visual representation of the Dietary Guidelines and shows a food-based plan for achieving adequate RDAs (Center for Nutrition Policy and Promotion, 2005).
6. The Montana Disability and Health Program has published a guide to minimum nutrition standards for adults with intellectual or developmental disabilities in formats for consumers (Humphries, Traci, & Seekins, 2005a) and for health support personnel (Humphries, Traci, & Seekins, 2005b).
Nutrition Education and Supports
In many places, licensing regulations for public or private institutions require that professionally trained and certified food service staff plan, prepare, and serve adequate diets to residents. Support staff in family, semi-independent, or group home settings generally do not have professional training or experience in nutrition and food service. We must develop new strategies to provide nutrition education, including environmental supports and procedures, for community-based service provider staff serving adults with intellectual or developmental disabilities. Adults with intellectual or developmental disabilities also need understandable and acceptable education and support materials so they may take conscious control over their diets and nutritional health.
It is the role of the nutrition or dietetics professional to provide accurate and easily understood nutrition information to both support staff and to those individuals who live independently and cook for themselves. The literature indicates that direct care staff need nutrition education on menu planning, cost containment, nutrition and health, and food safety (Walter, Cohen, & Swicker, 1997). Adults with intellectual or developmental disabilities need basic knowledge about healthy and less healthy foods, safe food preparation, meal planning, and the association between eating well and good health.
Community settings allow greater access to a wider range of unhealthful food choices than do institutions. If adults with intellectual or developmental disabilities are to live successfully and have adequate diets in community settings, they need better transition planning, community supports, and nutrition and foods education to expand the limited repertoire of healthful foods that they know how to buy and cook.
Effective nutrition education and supports must build on the individual's social network, and nutritional teaching materials must be interactive, visual, and culturally appropriate (Macario, Emmons, Sorensen, Hunt, & Rudd, 1998). Health promotion strategies for adults with intellectual or developmental disabilities should foster decision making and self-determination (Sutherland et al., 2002).
Last, we propose a working model that would establish consistency and clarify the relationships between nutrition and disability. We posit that nutrition relates to secondary conditions in adults with intellectual or developmental disabilities in four significant ways (Figure 1):
1. Nutrition may be a risk factor for secondary conditions, whereby poor nutrition, nutritional status, or eating habits put a person at risk for developing a particular secondary condition or making a secondary condition worse. Examples include weight problems, dental–oral hygiene problems, or osteoporosis.
2. Nutrition may be a protective factor in that good nutrition, nutritional status, or eating habits can prevent, delay, or improve a secondary condition. Examples include heart disease or nutritional deficits.
3. Nutritional deficiencies, such as iron-deficiency anemia, can be secondary conditions themselves. Poor nutrition, including anemia, in children with developmental disabilities is a risk factor for secondary learning problems, which may further affect their development (Ault, Guy, Rues, Noto, & Guess, 1994).
4. Many secondary conditions, such as diabetes and medication side effects, can affect one's diet and create subsequent secondary conditions and malnutrition.
This relationship model implies that an individual with a developmental disability may improve his or her nutrition to prevent, minimize, and improve secondary conditions and the life limitations they experience as a result.
*. Tables 2–5 are available in the online version of the journal:http://aaidd.allenpress.com/aamronline/request=index-html
Editor-in-Charge: Steven J. Taylor